The conventionally-known motor control device for torque control includes a motor constant calculator to calculate electric constants of a motor and corrects setting values of electric constants defined on one axis of orthogonal two axes (d-axis and q-axis) by a function expression using state variables defined on the same axis and by another function expression using state variables defined on the other axis (refer to e.g. patent document 1).
With this system the electric constants of a permanent magnet synchronous motor can be set more easily. As a result, by using the accurate electric constants to torque control, the torque control with higher accuracy is possible even when the torque is high, and the motor can be driven with high responsiveness and efficiency.